I bought a pair of DC41's 3 mo ago, and noticed one tipped over when using the hose with the machine upright. When I compared this to the machine that works correctly, I noticed that the arm in front of the ball which engages the carpet head in the upright position was stuck and would not come down, thus leaving the machine unstable. After jiggling the arm a bit, it became free, but it now won't stay up in the tilted vacuuming position. I then took off the filter cover, and a spring fell out. Again comparing to the functional machine, it was clear that the spring holds the arm up when vacuuming. I called customer service and brought the vac to the service center, but the man there is having a hard time understanding the lost function of the spring and the arm. Does anyone have an exploded diagram which shows the position of the spring and gimbal lock arm? It seems like the module containing the arm is secured by 3 screws on either side. I don't know how to remove the side of the ball that doesn't conceal the filter, otherwise I think I could access the location for the spring. How does that side of the ball come off?

My repair man came through. I picked up the machine yesterday and it works fine. Thank you Angus for your input, but I won't need any further assistance. I will remember this forum if I have any problems in the future.